**WEEK 5**

**Subject: Mathematics**

**Class: Primary 3**

**Term: 3 ^{rd} Term**

**TOPIC: Capacity**

**SUBTOPIC: Capacity addition and subtraction of liters**

**BEHAVIOURAL OBJECTIVES: At the end of the lesson, pupils should be able to:**

**Recapitulate the standard measurements of some liquid****Convert liters to centiliters****Add liters correctly****Subtract liters correctly**

**CONTENT**

**CAPACITY ADDITION AND SUBTRACTION IN LITERS**

Capacity is the measure of the amount of liquid in a container. The standard unit of

measuring capacity is the litre (*l)*

Small amount of liquid is measured in millilitre (*ml*) while large amount is measured in litres.

Table of capacity measure

10 milliliters (* ml*) = 1 centiliter (* cl*) 10 centilitres = 1 decilitre (*dl*)

10 deciliters = 1 litre (*l*) 10 litre = 1 decilitre (*dl*)

10 decilitres = hectolitre (*hl*) 10 hectolitres = 1 kilolitre (*kl*)

Note that

1 000ml * *= 1 litre ( *l* ) 100 *cl* = 1 litre 1 000 *l* = 1 kilolitre (*kl*)

When converting a smaller capacity measure to a higher one, note the following:

- a) From ml to
*cl*, divide by 10 b) From*cl*to*l*, divide by 100 - c) From ml to l, divide by 1 000 d) From
*l*to*kl*, divide by 1 000

**Examples**

- Convert 4 000ml to
*l =4000/1000l=4l* - Convert 600cl to
*l*= 600/100=6l

100cl = 6l

**Exercise 1**

Express the following in litres L

- 2 000ML 2. 1 200CL 3. 650cl 4. 800cl 5. 5 000ml
- 20 000ml 7. 900ml 8. 14 000ml 9. 700ml 10. 10 500ml

When converting higher capacity measure to a smaller capacity, note the following:

- a) From
*cl*to*ml*, multiply by 10 b) From*l*to*cl*, multiply by 100 - c) From
*l*to*ml,*, multiply by 1 000 d) From*kl*to*l*, multiply by 1 000

**Examples**

**Convert 6 litres to cl**

**1** l*ô* = 100 cl*ô*

6l = 100 × 6 = 600 cl*ô*

**Convert 5.5 l to ml**

1l * *= 1 000 ml

5.5l = 5.5 × 1 000 ml = 5 500ml

**Exercise 2**

**Convert the following to ml**

1. 7 cl 2. 6.5 l 3. 10l 4. 8.5 l 5. 12l

**Convert the following to ml**

1. 2l 2. 10 cl 3. 1.5 l 4. 3 cl 5. 4l

**Convert the following to l**

- 1.5 kl 2. 3kl 3. 4.3 kl 4. 0.8kl 5. 0.26kl
- 1.2 kl 7. 0.3 kl 8. 0.15 kl 9. 1.04 kl 10. 3.13kl

**Addition and subtraction involving litres**

**Examples**

- 2.38 l + 1.65 l

* ** *= 2 · 38 + 1 · 65 = 4 · 03 l

- 46.35l – 29.l6 l

* *= 46 · 35 – 29 · 16 = 17 · 19 l

**Exercise**

**Copy and complete the following.**

1. 4 · 3 + 2 · 4l

2. 7 · 9 + 8 · 6l

3. 14 · 3+ 9 · 8l

4. 8 · 42+ 3 · 25l

5. 5. 12 · 86+ 4 · 91

6. 15 · 63+ 14 · 78

7. 3 · 175+ 18 · 134

8. 13 · 217+ 19 · 893

9. 27 · 398+ 24 · 923

10. 34 · 654+ 27 · 678

11. 49 · 415+ 50 · 687

12. 5 · 6− 2 · 4l

13. 9 · 2− 5 · 4l

14. 11 · 8− 6 · 9

15. 7 · 43− 2 · 19l

16. 20 · 24− 8 · 77l

17. 32 · 03− 18 · 15l

18. 32 · 714− 16 · 250l

19. 46 · 038− 15 · 71l

20. 53 · 412− 26 · 891l

21. 60 · 105− 42 · 314l

22. 76 · 964+ 9 · 087

23. 795 · 22+ 900 · 11l

24. 900 · 85+ 25 · 22

25. 18.23l + 19.47l 26. 26.08l + 34.971l 27. 41.376l+ 39.8l

28. 30.317l – 12.888l 29. 46.053l – 18.94l 30. 61.7l – 45.632l

**TOPIC: Capacity**

**SUBTOPIC: Capacity multiplication and division of liters**

**BEHAVIOURAL OBJECTIVES: At the end of the lesson, pupils should be able to:**

**Multiply in liter by whole****Divide in liter by whole****Appreciate liter as the unit of capacity**

**CONTENT**

**Multiplication and division involving litres**

**Multiplication**

**Example**

Four cars each have 18.5 litres of petrol put in them. How much petrol is this?

18 · 5l

× 4

74 · 0

**Exercise 1**

Copy and complete the following.

1. 8·3l × 2

2. 7·1l × 8

3. 4·7l × 3

4. 5·9l × 4

5. 3.2l x 9

6. 9.4l x 7

7. 5.6l x 5

8. 6.2l x 6

9. 8.0l x 8

10. 1.7l x 9

11. 15.6l x 2

12. 27.9l x 8

13. 36.3l x 7

14. 47.9l x 6

15. 54.8l x 9

16. 68.4l x 3

17. 43.6l x 7

18. 52.2l x 9

19. 39.9l x 6

20. 20.7l x 8

**Division**

Example

Three customers bought 5.7 litres of palm oil and then

shared it equally among themselves. How many litres did

each customer get?

5.7l ÷ 3 = 1.9 *ô* 5.7 /3 = 1.9 *ô*

1.9 *ô*

3 √5.7

Each customer got 1.9 litres.

**Exercise 2**

Work these out using the method in the example.

1. 4.8 l ÷ 4. 2. 8.4 l ÷ 6 3. 7.2l * *÷ 9. 4. 8.0 * *÷ 5

5. 91.6/2*ô* 6. 74.7 /3. 7. 41.6/8*ô* 8. 53.6 /4

9. 3√ 17.1l 10. 7 √37.8l *ô* 11. 9 √66.6l *ô* 12. 5√ 89.5l *ô*

13. Divide 63.7 l*ôô*by 7 14. Divide 83.2 *ô* by 8

**Examples**

**Word problems on capacity**

- 1. A drum contains 12.58 litres of water, another drum contains 15.71 litres of water.

How much water will the two drums hold?

One drum contains = 12 . 58l

Another drum contains = 15 . 71l

Both drums hold = 28 . 29l

- A basin contains 30 litres of water. Bisi used 8.29 litres to wash. How much water is left in

the basin.

A basin contains 30 litres of water = 30 · 00 *ô*

+ 8 · 29

21 · 71 *ô*

used 8.29 litres

Amount of water left 30 – 8.29 litres

- A car tank holds 40 litres of fuel. How many litres can three such cars hold?

One car 40 litres

Three cars 40 × 3 litres = 120 litres

- 36 litres of milk was given to 4 pupils to share. How much milk will each pupil get?

No of litres to share = 36 litres 9 litres

4√ 36

36

No of pupils to share it = 4

One pupil will get = 36 ÷ 4

**Exercise 3**

**Word problems**

- 3.6l of water is poured into a bucket that already contains 2.9
*litres*of water. How much water is now in the bucket?

- A tank is full and it contains 30
*litres*of petrol. 12.72 litres of this is used. How much petrol is left in the tank?

- Five friends shared 4
*litres*of fanta equally. How many litres did each receive? - A station has only 92.4 litres of petrol left. This is shared equally by six customers. How many litres of petrol will each customer receive?

- A trader sells 43 bottles of oil a day. Each bottle contains 0.6 litres of oil. How many litres did she sell?

- Thirty-six children took 1.2 litres of water each with them on a journey. What was the total capacity of water taken?

- A car uses 8.76 litres out of the 30.92 litres of petrol in the tank. What capacity of petrol is left in the tank?

- A tanker emptied its water into two containers of 3 260 litres and 2 846 litres respectively. What is the capacity of the tank?

- A bucket of water contain 7.2 litres of water when full. Equal amount is given to four goats. What capacity of water will each goat drink?

- A driver bought 36.82 litres of petrol when traveling to Benin. On his way back he bought 48.45
*litres*. What is the total capacity of petrol bought?

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